An agricultural row crop planter is a machine built for precisely distributing seed into the ground. The row crop planter generally includes a horizontal toolbar fixed to a hitch assembly for towing behind a tractor. Row units are mounted to the toolbar. In different configurations, seed may be stored at individual hoppers on each row unit, or it may be maintained in a central hopper and delivered to the row units on an as needed basis. The row units include ground-working tools for opening and closing a seed furrow, and a seed metering system for distributing seed to the seed furrow. Wheels of the row units aid in the movement of the unit, and also act as closing devices to cover seed that is deposited into formed trenches for planting.
It is desirable to maximize crop yield to place seed in the ground at specified intervals and depth. Seed metering and sewing systems strive to do this today but are have inherent inaccuracy for a number of reasons. The sewing unit opens a trench with splayed disks pushed into the ground at the desire depth that the seed is to be buried. The trench is then packed by wheels and other devices. Inherent to the processes and apparatus, variation in soils type and moisture exist, and the seed trench depth can vary significantly. Because the seed is dropped from a metering device through a tube into an open trench from a moving tractor and then covered with soil, the position of the seed can vary significantly. The seed spacing interval as defined can also vary significantly because the sewing unit speed moving over the ground is calculated from tractor movement and planter geometry and can vary significantly in turns and other maneuvers.
Furthermore, because the seed meter may be bouncing erratically through the field, the seed can tumble through the seed tube striking it one or more times, particularly if the sewing unit is tilted on a hill and moving on rough terrain. The seed will tumble as it falls in the irregular trench in whatever orientation it happens to land before it is covered with soil. If the seed is not in the bottom of the trench it will move as the trench is closed with filling soil.
Therefore, there is a need in the art for overcoming problems associated with attempting to plant seed at a desired depth and with desired spacing intervals.